Bag compactor for conveying apparatus

ABSTRACT

A pallet loader of the type having a pallet elevator onto which patterns of articles, such as sacked material, are successively deposited and incrementally lowered for receipt of additional patterns, the loader having a movable wall above the elevator on which a pattern is disposed for transfer to the elevator, characterized by an elevator motion control which compacts a pattern while on the elevator and against the lower face of said wall. Pressure sensing means are associated with the wall for adjusting the force of compaction to a desired value.

United States Patent Dahlem et al.

[ 51, Oct. 17,1972

BAG COMPACTOR FOR CONVEYING APPARATUS Inventors: Billy J. Dahlem, Golden; John A.

Martin, Denver, both of Colo.

Power-Curve Conveyor- Company, Denver, Colo.

Filed: Sept. 29, 1969 Appl. No.: 861,979

Assignee:

US. Cl. ..2l4/6 DK, 214/6 H Int. Cl ..B65g 57/24 Field of Search ..214/6 DK, 6 H, 6 P

References Cited UNITED STATES PATENTS Boehl et al. .,214/6 P Miller, Jr. ..2l4/6 P X 3,567,046 3/1971 Reist ..2l4/6 H Primary Examiner-Robert J. Spar Attorney-Sheridan, Ross and Burton and Victor C.

Muller [57] ABSTRACT A pallet loader of the type having a pallet elevator onto which patterns of articles, such as sacked material, are successively deposited and incrementally lowered for receipt of additional patterns, the loader having a movable wall above the elevator on which a pattern is disposed for transfer to the elevator, characterized by an elevator motion control which compacts a pattern while on the elevator and against the lower face of said wall. Pressure sensing means are associat'ed with the wall for adjusting the force of c0mpaction to a desired value.

1 Claim, 5 Drawing Figures PATENIEDum t 7 (972 3 698, 572

IOO

Open Curtain(drop pattern to elevator) -Lower Elevator (pattern beneath curtain) Close Curtain F?aise Elevator (compact) -Cease Raising Eievator(maintain compaction) -Lower Elevator (cease compaction) L IIIII/lm V2 INVENTORS JOHN A. MARTIN l l BY BILLY J. DAHLEM g: 1 i/zgo. 0 J

ATTORNEYS BAG COMPACTOR FOR CONVEYING APPARATUS BACKGROUND OF THE INVENTION In the application of Billy J. Dahlem, Ser. No. 778,591, filed Nov. 25, 1968, for Pallet Loading Apparatus, and now U.S. Pat. No. 3,587,876 a loading station vertical compactor is disclosed (FIG. 9 of same) which compacts a pattern of articles, such as sacks of SUMMARY OF THE INVENTION The present invention comprises a modification of the construction just refer ed to in that compaction of the pattern takes place while it is disposed on the elevator, rather than prior to transfer of the pattern to the elevator. The elevator construction is essentially the same but its control is modified so that after transfer ring an uncompacted pattern from the top face of the curtain to the elevator, the elevator lowers to permit the curtain to close, as formerly, after which the elevator raises and compacts the pattern against the lower face of the curtain. With this construction, the top surface of a previously compacted pattern on the elevator becomes the lower pressure face for compacting the pattern disposed on same and, since the material in the sacks may reorient in same upon compaction, the compaction is such that the interfaces come into more intimate contact, filling minor voids and thus effecting an improved tie between the compacted patterns. This may perhaps be better understood by considering the nature of the upper surface of a pattern when it engages the roller curtain during compaction. It is essentially flat but may have minor ripples or irregularities caused by the shape of the rollers. When this surface engages the lower surface of the next pattern being compacted, the major compaction takes place in the uppermost pattern but some further compaction also takes place in the top face of the pattern beneath same, producing a more intimate contact between these two generally flat surfaces and substantially eliminating any voids therebetween, thereby improving the tie as compared with stacking compacted patterns on each other and without compaction therebetween after stacking. In addition to the advantage just referred to the apparatus is simplified since the former separate compactor disposed above the curtain and its actuating mechanisms are eliminated and the elevator performs its function by relatively slight modification to its motion control and relatively minor modification to the curtain construction. An additional feature resides in some improvement in the rate of operation of the entire pallet loader in that if a predetermined time of maintaining compaction is desired while a pattern is disposed on the elevator, this time does not detract from the timing of previous operations. Thus, if a desired time of compaction were desired on top of the curtain in the previous construction referred to the timing of movement of articles prior to delivery to the curtain would require coordination with compaction time. The elevator, however, operated only intermittently and for short intervals of time. In the present invention the former idle time of the elevator may be utilized for compaction time, thereby permitting some overall gain in rate of operation of the entire pallet loader.

It is thus a principal object of the invention to provide a pallet elevator and method of control for same for compacting a pattern while disposed on a pallet elevator, as distinguished from compaction prior to transfer of the pattern to the elevator.

Another object is to provide a curtain construction and pressure sensing apparatus which may be adjusted to provide a desired compaction pressure on the pattern.

A further object is to maintain compaction for a desired time, which time utilizes former idle time of the elevator.

Still further objects, advantages and salient features will become more apparent from the description to follow, the appended claims and the accompanying drawing to now be briefly described.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 schematically illustrates a side elevation of the subject of the invention;

FIG. 2 is a section taken on line 2-2, FIG. 1;

FIG. 3 is a side elevation as viewed in the direction of arrows 3-3, FIG. 2;

FIG. 4 diagrammatically illustrates a stepping switch, and

FIG. 5 is a longitudinal section through an alternative form of loading station platen.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, FIG. 1 is a composite view of portions of FIGS. 2 and 15 of the copending application referred to with certain modifications to be subsequently described, its purpose being to illustrate the general organization with which the invention is associated. Briefly, this comprises accumulator station 28 on which a pattern is formed, a loading station 30 which includes link connected rolls 80, forming a movable curtain, and an elevator having a pallet supporting platform 93 which may be raised or lowered by a hydraulic ram under control of pump P, valves V V and solenoid valve actuators S S the fore going reference characters, except for S S corresponding to those of the copending application. The mode of operation is the same, also, to the extent that a pattern is formed on the accumulator station, is then transferred to the loading station where it may optionally be laterally compacted, after which the curtain translates, permitting the pattern to drop onto pallet p, disposed on the top of the elevator, the elevator generally descending incrementally as the patterns are stacked thereon. While there is a general incremental descent of the elevator, as just described, it also has a powered upward movement between the incremental descents for compacting a pattern disposed on same, as will more fully appear, which function is not described in the copending application.

Referring now to FIG. 2, idler rolls 80 are connected at their ends to chains 11 which move synchronously under power, the lower runs of the chains being guided along guides 13, also employed in the copending disclosure. One of the modifications, however, includes bars 15 disposed above each chain which are supported by studs 17 and angle brackets 19 which are vertically adjustable with respect to fixed frame 21, springs 23 being disposed between the brackets and bar. The resilient force exerted on the bar may be adjusted by moving the brackets vertically, as permitted by slots 25, and the setting of stop screws 27, after which they may be locked by clamp screws 29. A nut 31 is provided on each stud to position the bar a slight clearance distance above the chain so that the chain does not engage the bar when it is in motion. One or more micro-switches 33 (FIG. 3) are disposed adjacent the bar which are engaged by same when it moves to a certain position as will be hereinafter set forth. If more than one switch is employed the switches are preferably wired in series so that the last switch actuated establishes an electrical circuit.

For simplicity of disclosure it will first be assumed that the various instrumentalities are under manual control, the operation being as follows: let it first be assumed that a pattern has been bodily transported to the top of the curtain and the curtain is free to move. The curtain is then actuated to open position, dropping the pattern onto the pallet or onto the top pattern of a stack of patterns thereon. The elevator is then lowered to a position such that the top of the pattern is below the lower plane of the curtain and the curtain is then moved to closed position. Valve V (FIG. 1) is then opened and pump P supplies fluid to ram 100, raising the elevator and compacting the pattern against the lower plane of the curtain. The chains and rolls then bodily move upwardly, the chains engaging bars 15 which move upwardly against the urge of springs 23. When the bars operate the micro-switch or switches 33 a signal is established that a predetermined compacting force on the pattern has been attained and in response to this signal valve V is closed allowing the force to be maintained for a desired interval of time, after which valve V is opened to permit the elevator to descend a distance sufficient to lower the top pattern on same out of engagement with the curtain so that it may again be actuated to open position when the next pattern is to be dropped onto the now compacted top pattern on the elevator. Normally, this interval will be until a signal is received that a pattern formed on the accumulator station is ready for transfer to the loading station curtain, and as will be apparent, the curtain rolls should be free to rotate during this transfer or, as otherwise stated, compaction should cease somewhat before the transfer.

In an actual form of the invention the sequence of operation just described is performed automatically by limit switches which are actuated in desired sequence by motion of the machine parts. This, per se, however, forms no part of the invention and, as will be apparent, a myriad of other forms of controls will become apparent to those skilled in the art. To further simplify the disclosure and obviate unnecessary circuitry which is not germaine to the invention, a simplified automatic control is illustrated in FIG. 4 whe ei a e uencin switch S may be assumed to step at desi red in ervals t establish circuits which will operate the various instrumentalities and which is self-explanatory, conforming to the manual mode of operation previously set forth.

As so far illustrated and described, the top of loading station 30 is formed as a curtain comprising side chains and parallel rolls connected to the chains which may be characterized as a translatable wall. Normally, the upper and lower faces of such wall should be generally flat and parallel, thus forming generally planar surfaces. As will be appreciated, however, the translatable will may be of a form other than a roller curtain; for example, it may be of the form as shown in FIG. 10 of the application referred to and FIG. 5 of the present application, wherein it is formed as a rigid platen 114 having parallel upper and lower faces, the platen being translatable rectilinearly between two positions and without movement between lower and upper flights as in the roller curtain, first described.

What is claimed is:

1. In apparatus of the type for loading a plurality of generally rectangular articles onto a support, such as a pallet, in a plurality of layers of like patterns, said articles in each layer being in the form of a plurality of sacks each containing material subject to reorientation and compaction in response to a compaction force against opposite sides thereof, said apparatus including a vertically movable planar elevator on which the support is removably disposed and having a translatable generally planar wall above same to which a layer of uncompacted articles may be delivered, the support, when loaded, adapted to be removed from the elevator in a lateral direction when in its lowered position, the improvements, in combination, comprising, and operable in the order named;

a. means for restraining said wall against substantial upward movement, when in closed position above the elevator,

b. means for translating the wall to open position to deposit an uncompacted pattern disposed on same onto the elevator,

c. means for lowering the elevator to a position such that the pattern is disposed beneath the lower plane of the wall,

d. means for moving the wall to closed position,

e. means for raising the elevator to vertically compact the pattern between same and the lower plane of the wall, said lower plane being so constructed to abut the top of the pattern over a substantial area thereof and reorient the material therein to a shape in which its upper and lower faces are generally flat and parallel, the lower face also adapted to compact the upper face of a pattern below same and conform the abutting faces to a shape substantially without voids therebetween,

f. resiliently urged members disposed adjacent lateral edges of said wall, to permit it to rise during compaction, and

g. switching means operable in response to predetermined pressure on said members for terminating increase in compaction pressure, whereby compaction pressure may be limited to a desired value. 

1. In apparatus of thE type for loading a plurality of generally rectangular articles onto a support, such as a pallet, in a plurality of layers of like patterns, said articles in each layer being in the form of a plurality of sacks each containing material subject to reorientation and compaction in response to a compaction force against opposite sides thereof, said apparatus including a vertically movable planar elevator on which the support is removably disposed and having a translatable generally planar wall above same to which a layer of uncompacted articles may be delivered, the support, when loaded, adapted to be removed from the elevator in a lateral direction when in its lowered position, the improvements, in combination, comprising, and operable in the order named; a. means for restraining said wall against substantial upward movement, when in closed position above the elevator, b. means for translating the wall to open position to deposit an uncompacted pattern disposed on same onto the elevator, c. means for lowering the elevator to a position such that the pattern is disposed beneath the lower plane of the wall, d. means for moving the wall to closed position, e. means for raising the elevator to vertically compact the pattern between same and the lower plane of the wall, said lower plane being so constructed to abut the top of the pattern over a substantial area thereof and reorient the material therein to a shape in which its upper and lower faces are generally flat and parallel, the lower face also adapted to compact the upper face of a pattern below same and conform the abutting faces to a shape substantially without voids therebetween, f. resiliently urged members disposed adjacent lateral edges of said wall, to permit it to rise during compaction, and g. switching means operable in response to predetermined pressure on said members for terminating increase in compaction pressure, whereby compaction pressure may be limited to a desired value. 